C#/.NET + React | $160k–$180k Base + Super + Bonus | Sydney CBD Onsite
A fast-moving fintech scale-up is hiring a Senior Software Engineer to help own the customer-facing systems that bring users in, get them verified, and get them live.
This is the front door to the product: the public website, sign-up, onboarding, identity, activation, and the digital experiences that shape every customer’s first impression of the business.
If you enjoy building across the full stack, care about performance and customer experience, and understand the importance of secure, reliable software in a financial services environment, this could be a very strong move.
About the role
As a Senior Software Engineer, you will work across backend and frontend engineering, helping deliver secure, scalable, and high-performing digital product experiences.
You will not be tucked away in a narrow backend-only role. This position sits close to product, design, customer acquisition, and onboarding, so the work you ship has a direct impact on growth, conversion, and customer trust.
Working alongside the Engineering Manager, Product Owner, UX Designer, and fellow engineers, you will:
- Build and maintain customer-facing product features across the website, onboarding, sign-up, identity, and activation flows.
- Work across backend APIs and services in C#/.NET, plus frontend product development in React and TypeScript.
- Contribute to technical direction, architecture, and engineering standards within the squad.
- Take ownership of features end-to-end, from shaping the solution through to production and ongoing improvement.
- Write clean, readable, testable code and help maintain a high bar through code reviews.
- Build secure, reliable digital experiences suitable for fintech and financial services customers.
- Care about frontend quality, including performance, accessibility, SEO, Core Web Vitals, and conversion.
- Support multi-region and multi-lingual digital experiences, including i18n, l10n, and related routing or infrastructure patterns.
- Proactively identify and improve performance, reliability, and quality issues.
What we are looking for
- Strong full-stack engineering capability, with solid C#/.NET backend experience and strong React and TypeScript frontend skills.
- Commercial experience working in fintech, financial services, payments, banking, lending, insurance, wealth, trading, or another regulated or customer-data-heavy environment.
- A track record of shipping quality software in a product environment with real users.
- Strong understanding of secure engineering practices, especially around customer data, authentication, onboarding, and reliability.
- Experience with content-driven or headless CMS architectures.
- Good knowledge of technical SEO, structured data, crawlability, frontend performance, and Core Web Vitals.
- Experience building scalable, maintainable customer-facing platforms.
- Genuine ownership, with care for what happens after the code is merged.
- Strong engineering judgement around edge cases, failure modes, maintainability, and performance.
- Enough frontend sensibility to care about user experience, conversion, and polish, not just functional correctness.
- A collaborative, commercially curious mindset, with comfort working in a fast-moving fintech environment.
Nice to have
- Experience with onboarding, identity verification, KYC, KYB, or customer activation flows.
- Familiarity with SSO protocols such as OAuth 2.0, OIDC, or SAML.
- Experience working with multi-region or multi-lingual products.
- Strong frontend performance experience across Lighthouse, accessibility, and cross-device optimisation.
- Background in fintech, e-commerce, payments, or other high-conversion digital product environments.
The offer
- $160,000–$180,000 base salary + superannuation + bonus.
- A senior engineering role with genuine ownership and visible product impact.
- High-impact customer-facing product work across onboarding, identity, and activation.
- A fast-moving fintech scale-up with strong momentum.
- Sydney CBD location.
- Five days a week onsite, working closely with a sharp, collaborative engineering and product team.
About Big Wave Digital
This search is being run by Big Wave Digital, a specialist technology recruitment partner working with some of Australia’s most interesting tech and fintech businesses.
We work closely with both the companies we represent and the people we place, so you will get clear context, straight answers, and someone in your corner throughout the process.
Sound like you?
Apply now with your CV, or reach out for a confidential chat.
Big Wave Digital is placing this role directly with the hiring team, so your application goes straight to a decision-maker rather than disappearing into a queue.
If you are a Senior Software Engineer with strong C#/.NET, React, and fintech or financial services experience, this is a standout opportunity to join a scaling product business where your work will genuinely matter.
